1. Field of the Invention
A developing-transferring module and image forming apparatus having the same in accordance with the present general inventive concept relate to improving a development configuration and a transfer configuration to minimize a color alignment deviation.
2. Description of the Related Art
In general, an image forming apparatus visualizes an image data to a record medium depending on a print signal supplied from a host. The image forming apparatus includes a record medium supplying unit loading the record medium, an image forming unit forming an image to the record medium of the record medium supplying unit, and a record medium discharging unit discharging the record medium formed with the image. In the image forming apparatus, there are a mono type visualizing the image data to the record medium in a black and white image, and a color type visualizing a color image to the record medium by a combination of four color (yellow, magenta, cyan and black) developers.
FIG. 1A is a schematic view illustrating a configuration of a conventional color type image forming apparatus 10. As illustrated therein, a conventional image forming apparatus 10 includes a record medium supplying unit (not illustrated) loading a record medium using a developing roller 22 and a photosensitive body 21, developing units 20Y, 20M, 20C and 20K of each color applying a developer to the record medium using a developing roller 22 and a photosensitive body 21, a intermediate transferring belt 41 sequentially transporting the record medium to the developing units 20Y, 20M, 20C and 20K of each color and transferring the developer to the record medium, and a light exposing unit 30 scanning light to the photosensitive body 21 to form an electrostatic latent image on the photosensitive body 21.
An image forming method of the conventional image forming apparatus 10 is as follows. If a print signal is supplied from a host, a record medium picked up from the record medium supplying unit is transported along the intermediate transferring belt 41, and is contacted with the photosensitive body 21 of the developing unit 20 of each color. Here, a transferring roller 45 provided to a rear surface of the intermediate transferring belt 41 to correspond to the photosensitive body 21 of each color supplies a predetermined transferring voltage to transfer a developer on a surface of the photosensitive body 21 to the record medium, thereby forming an image. Here, at least two color developers are overlapped. The record medium is formed with a color image of various colors, and is discharged to the outside.
Here, if an alignment of the developer of each color applied to the record medium according to transporting of the intermediate transferring belt 41 aligns with each other, an image having a clear color is expressed as illustrated in area L of FIG. 1B. However, if the alignments of the developers of different colors do not accurately align with each other, color of an image data printed to the record medium is not clear as illustrated in area M of FIG. 1B, thereby deteriorating a print quality.
In the conventional image forming apparatus 10, each developing unit 20 is separated one another, and the intermediate transferring belt 41 is provided to be separable since the intermediate transferring belt 41 should be separated from the developing unit 20 if a record medium jam occurs on the intermediate transferring belt 41. Accordingly, a color alignment inferiority may be due to an assembling tolerance between the plurality of photosensitive bodies 21 and the intermediate transferring belt 41 in separating and coupling of the intermediate transferring belt 41, a meandering of the intermediate transferring belt 41, and a un-uniform line speed of the intermediate transferring belt 41, etc.
Also, if the temperature of the inside of the image forming apparatus 10 increases due to a long time use, a color alignment inferiority due to the un-uniform line speed because of heat deformation of a driving roller 43 of the intermediate transferring belt 41, and an angle variation of a reflecting mirror because of heat deformation of a frame of the light exposing unit 30 is caused.
To solve the color alignment inferiorities, the conventional image forming apparatus corrects the color alignment inferiorities through an auto color registration. However, if the auto color registration is executed, a separate time is necessary to provide the auto color registration after supplying of a print signal, and a print time is delayed despite printing a single record medium. Accordingly, inconvenience to a user occurs.